Air screen for jet engines



NOV. 18, 1952 p, NEWCQMB 2,618,358

AIR SCREEN FOR JET ENGINES Filed Jan. 20, 1951 3 Sheets-Sheet l 0 N 1- & N

I) x a R Q Q w a w a \1 k Razz/3 9.1 ma ma @auewa idov-zaep,

P. P. NEWCOMB AIR SCREEN FOR JET ENGINES Nov. 18, 19.52

3 Sheets$heet 2 Filed Jan. 20, 1951 u venior 2 N4 B w 1 W P 1952 P. P. NEWCOMB AIR SCREEN FOR JET ENGINES 5 Sheets-Sheet 3 Filed Jan. 20, 1951 W? 00 .2 m n Patented Nov. 18, 1952 NIT-ED TSTATES ATE-NT OFFICE AIR SCREEN FORIJET'LENGINES .9 Philip. P. Newcomb; Manchester;.Oonngzassignor to-UnitediAircraft .Qorporation,EaStHartford, Conn, aicorporaition (if-Delaware ..";Aiiplic*ation January 20,"1'951,--Serial-No.*20'6,963

37 Claims. (01.11831162) .1i This?invention relates'to a screen'for thei 'air substahtially coni-plete screen-for thea'nnular in- :lvt inletwf azpower plant'and particularly to arelet. The segments extend across the inletberactable screen"for usein. thei-gas turbine type 'tween theforwardedge' of thesleeve ill and the .It OfpOWef plant, 'cone 4 an'd-are-in substantiallyedgewise'engage- 3 '1 lt has been ifoundiadvantageous to provide a 5 ment; Although the particular structure of each vilscreento.preventthe entrance of:foreign material screen segment is not critical, the structure ntozthe' power-plantinletsparticularlywhile the shown involves a. number of' radially extending ....,.powe1-::plant isiopera'ting:onzthe'ground or at low webs l6 circuinfer'entially spaced apart and a i altitudesns'lsuch. ariscreenwhowever; inevitably numb-er of intersectingcircumferentially extend- 2::.:.impedesithei:flow: ofaair'c-intcxthe inlet to some ing'webs 18 which are radially spaced apart' As -'-:taextent"tandtaecordingly" the'ause oftthis :screeninbest shown in Fig. 3the-radiallyextending-webs volves some loss of power in thepower plant. A are notched as at 2t! to receive thetra iling edges iiz featureiofithis invention istan arrangement for of the circumferenti'ally extending webs and the isretractingzthescreen:into a pcsitionwhere it will assembly of webs i's'hld in position by a sur- :::not.-impecleithe flow'zwhen' the screen is'not wounding substantially continuous frame 22. :eneeded. "Two of the assemblies of intersecting webs with i :In manyinstances theainin'let to aga's turbine the'surrounding frame-22 are held together as -typetof power plant is: annularjfor directing the by a connecting pin'24 at the inner endsarid by a :s flovw ofiair-intnlthe compressor; feature of the connecting bracket 25 at the cuter'ends to define reinvention is asscreenm'ade' up-' of "separate seg- 20 a screen segmentnhaving a centrally located trments whichscanrbesmovedinto or'out of operaradially extending 's'lot'28; frames are se- 'zrs'tive position in the: annular air-passage. An- -:curely connected to br'acketZB to move therewith. other feature isiani arrangement fo'r simultanerEach segment is pivotally supported at its outer :3 :zouslyr retracting all of the segments at one :time "end'on a 'pin 39; Figs. 2 and 3, which provides a ir-into antinoperativetposition. Wpivotal support for :the. bracket "25. I'he pin=3il e: Other objects zand advantages will. be apparent "ex-tends'ibetween" spaced. supporting members" 32 awtromftherspecification .i'ajnclv ic-1aims,and" from the "which are sliclable'on supporting rods 36' extend- -n'accompanying'drawingsfwhich; illustrate faneming'in a direction substantially parallel to the :m-bodimentiofthe'invention. flow" of 'air through the duct. -Each ofthe 'in'em- ,5; Fi -1 i avperspective yiewof. a paw er: plant;:,30rb'ers"32"has an'integral sleeve "portion 3'6 which 1*inletrlshowing"thev'screen-inioperative'i'position slides 'onth'e'rodt i.- Each pair of rods'34 may exceptffcronesegment'which is; inzthe-inoperabe mounted'on" thef cewling' 8 asby" mounting z tive position. brackets 38 at "the upstream end and other ":Fig..2 isa-front'elevation of the screen andsup- 1 brackets 39' at the downstream end. 1': porting structure with-vparts brokenaway. :i ;In' retractin 'the. screen segments from opera Fig: 3yis azsectionaL-view; substantiallyromthe 3 tiver position iacross 'the inlet',?the supporting line-3+3rofiFig 2. memher's 32 for each segment iarepulledrear- :Fig; ids a fragmentary;sectional view along wardly by means of a rod in the forward .end' 'of the line 4-4 of Fig.2. which is pivotallyitmountednn'pinfell and the ;'-,.-;Fig. is afragmentaryrsectional': view al-ongjgnouother end ofxwhich: isvthreadedzto engage with r ztherline-5 -a5 ofiEig. 2. cooperating -:.threads ion the inner surface ofa I'=.-"Th8 invention isishownasappliedttoithe'inlet sleeve-62.; Thisl'slceve" isrjcmnalled: in a" bracket of ages turbine type ofpower. plant in which the M which is attached torthe'fixed'sleevel if! so that screen '2:;extends:between; the; inner cone '43 definas the sleeve 42 is turned in one direction the rod ingcthesinnerwallnf the .annular'inletpassage 5 45-1 40 is pulled-"rearwardlycausing the screen to pivot andtthe cowling 8':'.which:,forms-in general the forwardlyrinto' the-'spositi'cn' shown'by theidotted onter'y'vall'iofzthepassa eg:Asiishown intFig'. 3 a vilines,-;-Fig. 3.

gesleeve l0 ,zlocated: within-.anflespaced fromithe At the-sameztime that t'hEI-Od48 isEb-eing-pulled cQwling .8:f0rm's a-zpart'foi. the outer wall 'of the rearwardly, a movable sleeve ili surrounding and ieinJet-rductzrand cdeifines atspaceT'lZ between the-:i-isubstantially;in-contact-:withthe'"sleeve: It" is rs-scowling." fand' rsleeve' which encloses the actuating moved. forwardly to form Y an extensiom of "the firmechanismsfor the'screen. i sleeve ll): :Foractuating the sleevei ie the'sleeve FASZShOWIliiiLFigS/lfiifld 2.the.screen is made up 142:;hasiexternal ifthreads.JQB- engaging with a ofizindividuaiisegment shapedelementsxlt which threaded bracket? 0': attached tolxthe rearward ohm theoperativemosit'roniof:Eigs. liand 2 form ai eendr ofzsleeveeeo.n;lt iwilltbe;notedpassshown m Fig. 5, that the sleeve 46 is slotted to fit around the brackets 44. The threads 48 are opposite to the threads engaging with the rod 40 so that when the rod is pulled rearwardly the sleeve 45 will be moved forwardly. The forward end of this sleeve engages and rides alon on the back surface of the screen such that the screen is caused to swing down into retracted position more rapidly than if the sleeve 46 remained stationary.

In the retracted position of the screen, at which time the sleeve 46 is in its forward position (the dotted line position of Fig. 3), the sleeve 46 holds the several screen segments against the frustoconical ring 52 which forms a rearwardly projecting extension on the in-bent forward end 54 of the cowling 8. The ring 52 is provided with spaced notches 56 which provide a resilience for the ringin a radial direction so that the screen segments are held resiliently against the sleeve 46 when the segments are in the retracted position,

When the screen is moved into operative position by moving the supporting pin forwardly and at the same time retracting the sleeve 46 the screen is resiliently pulled into its operative position by means of a rod 58 having a laterally projecting pin 60 in its forward end which, as best shown in Fig. 2, overlies the portions of the supporting frame 22 which define the opposite walls of the radially extending slot 28. This slot provides a space for the rod 58 to move through during the retraction of the screen. The other end of the rod 58 is pivoted on a link 62 which in turn is pivoted on a bracket 54 on the sleeve 45. A coil spring 66 extends between the rearward end of the rod 58 and another bracket 68 on the sleeve 46 thereby resiliently holding the screen in such a position that it is in engagement with the sleeve 46 at all times.

For actuating the several threaded sleeves 48 for simultaneous movement of all of the screen segments, each sleeve carries a sprocket 19 at its forward end adapted to engage with an endless chain 12 which passes over all of the sprockets and also over a driving sprocket 14 on the shaft 16 of a suitable driving means such for example as a geared motor 18. The chain passes over the outer sides of the sprockets H! and over the inner surface of sprocket 14 as shown. For keeping the chain 12 under suitable tension the motor 78 is mounted on trunnions 86 and at a point adjacent the sprocket is supported on coil springs 82 which engage with lugs 84 on the motor. In this arrangement the springs 82 continuously tend to move the sprocket end of the motor radially inwardly in a direction for tightening the chain.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims,

I claim:

1. A screen for a power plant having a duct through which air flows, said screen including a series of grids each forming a segment of the screen and together forming a closure wall in said duct, a pivotal support for each grid, means for pivoting said grids into a position parallel to and out of the path of the air flow in said duct, and means for moving all of said grids as a unit into inoperative position, said last means including a cylinder forming a part of the outer wall of the air duct and engaging with said grids, and means '4 for moving said cylinder axially to cause pivotal movement of the grids on their pivots.

2. A screen for a power plant having a duct through which air flows, said screen including a series of grids each forming a segment of the screen and together forming a closure wall in said duct, a pivotal support for each grid, means for pivoting said grids into a position parallel to the path of the air flow in said duct, and means for moving all of said grids as a unit into inoperative position, said last means including a cylinder forming a part of the outer wall of the air duct and engaging with said grids, and means for moving the pivotal axis of the grids axially to cause pivotal movement of the grids into or out of operative position.

3. A screen for a power plant having a duct through which air flows, said screen including a. series of grids each forming a segment of the screen and together forming a closure wall in said duct, a pivotal support for each grid, means for pivoting said grids into a position parallel to the path of the air flow in said duct, and means for moving all of said grids as a unit into inoperative position, said last means including a cylinder forming a part of the outer wall of the air duct and engaging with said grids, means for moving said cylinder axially to cause pivotal movement of the grids on their pivots, and means for moving the pivotal axis of the grids axially to cause pivotal movement of the grids into or out of operative position.

4. In a gas turbine power plant having an annular gas path, the combination of a device adapted to be positioned in the gas path, said device being made up in segments, a pivotal support for each segment located outside of the gas path, means spaced from said pivotal supports and engaging with said segments, and means for shifting the pivotal supports axially for pivoting said segments into or out of operative position, said segments in inoperative position being located outside of the gas path.

5. In a gas turbine power plant having an annular gas path, the combination of a device adapted to be positioned in the gas path, said device being made up in segments, a pivotal support for each segment located outside of the gas path, means for shifting the pivotal supports axially as a unit for causing movement of said segments into or out of operative position, said segments in inoperative position being located outside of the gas path, and means engageable with said segments and movable in a direction opposite to the movement of the pivotal supports during movement of the segments into inoperative position, said last means forming an exten sion of a part of the wall defining the gas path and enclosing said segments.

6. A gas turbine power plant having an annular air inlet, in combination with a screen for said. inlet comprising a series of grids each forming a segment of the screen and together forming a substantially continuous screen extending across the annular air path, a pivotal support for each segment located outside of the air path, and means for moving said segments about their pivots into a position out of the air path, said means including a sleeve forming a part of the wall of the air path and engaging with said segments at a point spaced from the pivotal support for each segment, and means for moving said sleeve axially to cause pivotal movement of said segments.

7 A gas turbine power plant having an annular air inlet, .in combination with ascreen for said inlet comprising a series of grids each forming a segment of the screen and together forming a substantially continuous screen extending across REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Marshall Dec. 12, 1950 De Remer Mar. 2'7, 1951 Kelly June 5, 1951 

